1. Field of the Invention
The present invention generally relates to data base management systems and more particularly relates to enhancements for dynamic tracing within an environment wherein users request information from the data base management system via the Internet.
2. Description of the Prior Art
Data base management systems are well known in the data processing art. Such commercial systems have been in general use for more than 20 years. One of the most successful data base management systems is available from Unisys Corporation and is called the MAPPERxe2x86x92data base management system. The MAPPER system can be reviewed using the MAPPER User""s Guide which may be obtained from Unisys Corporation.
The MAPPER system, which runs on proprietary hardware also available from Unisys Corporation, provides a way for clients to partition data bases into structures called cabinets, drawers, and reports as a way to offer a more tangible format. The MAPPER data base manager utilizes various predefined high-level instructions whereby the data base user may manipulate the data base to generate human-readable data presentations. The user is permitted to prepare lists of the various predefined high-level instructions into data base manager programs called xe2x80x9cMAPPER Runsxe2x80x9d. Thus, users of the MAPPER system may create, modify, and add to a given data base and also generate periodic and aperiodic updated reports using various MAPPER Runs.
However, with the MAPPER system, as well as with similar proprietary data base management systems, the user must interface with the data base using a terminal coupled directly to the proprietary system and must access and manipulate the data using the MAPPER command language of MAPPER. Ordinarily, that means that the user must either be co-located with the hardware which hosts the data base management system or must be coupled to that hardware through dedicated data links. Furthermore, the user usually needs to be schooled in the command language of MAPPER (or other proprietary data base management system) to be capable of generating MAPPER Runs.
Since the advent of large scale, dedicated, proprietary data base management systems, the internet or world wide web has come into being. Unlike closed proprietary data base management systems, the internet has become a world wide bulletin board, permitting all to achieve nearly equal access using a wide variety of hardware, software, and communication protocols. Even though some standardization has developed, one of the important characteristics of the world wide web is its ability to constantly accept new and emerging techniques within a global framework. Many current users of the internet have utilized several generations of hardware and software from a wide variety of suppliers from all over the world. It is not uncommon for current day young children to have ready access to the world wide web and to have substantial experience in data access using the internet.
Thus, the major advantage of the internet is its universality. Nearly anyone, anywhere can become a user. That means that virtually all persons are potentially internet users without the need for specialized training and/or proprietary hardware and software. One can readily see that providing access to a proprietary data base management system, such as MAPPER, through the internet would yield an extremely inexpensive and universally available means for accessing the data which it contains and such access would be without the need for considerable specialized training.
There are two basic problems with permitting internet access to a proprietary data base. The first is a matter of security. Because the internet is basically a means to publish information, great care must be taken to avoid intentional or inadvertent access to certain data by unauthorized internet users. In practice this is substantially complicated by the need to provide various levels of authorization to internet users to take full advantage of the technique. For example, one might have a first level involving no special security features available to any internet user. A second level might be for specific customers, whereas a third level might be authorized only for employees. One or more fourth levels of security might be available for officers or others having specialized data access needs.
Existing data base managers have security systems, of course. However, because of the physical security with a proprietary system, a certain degree of security is inherent in the limited access. On the other hand, access via the internet is virtually unlimited which makes the security issue much more acute.
Current day security systems involving the world wide web involve the presentation of a user-id and password. Typically, this user-id and password either provides access or denies access in a binary fashion. To offer multiple levels of secure access using these techniques would be extraordinarily expensive and require the duplication of entire databases and or substantial portions thereof. In general, the advantages of utilizing the world wide web in this fashion to access a proprietary data base are directly dependent upon the accuracy and precision of the security system involved.
The second major problem is imposed by the internet protocol itself. One of the characteristics of the internet which makes it so universal is that any single transaction in HTML language combines a single transfer (or request) from a user coupled with a single response from the internet server. In general, there is no means for linking multiple transfers (or requests) and multiple responses. In this manner, the internet utilizes a transaction model which may be referred to as xe2x80x9cstatelessxe2x80x9d. This limitation ensures that the internet, its users, and its servers remain sufficiently independent during operation that no one entity or group of entities can unduly delay or xe2x80x9chang-upxe2x80x9d the communications system or any of its major components. Each transmission results in a termination of the transaction. Thus, there is no general purpose means to link data from one internet transaction to another, even though in certain specialized applications limited amounts of data may be coupled using xe2x80x9ccookiesxe2x80x9d or via attaching data to a specific HTML screen.
However, some of the most powerful data base management functions or services of necessity rely on coupling function attributes and data from one transaction to another in dialog fashion. In fact this linking is of the essence of Mapper Runs which assume change of state from one command language statement to the next. True statelessness from a first MAPPER command to the next or subsequent MAPPER command would preclude much of the power of MAPPER (or any other modern data base management system) as a data base management tool and would eliminate data base management as we now know it.
Providing the system with the capability to save the needed information from transaction to transaction, permits applications to be developed for a true dialog-type interface between the legacy data base management system and an Internet terminal. As a result, it becomes important to offer certain useful debug features. However, typical run-time tracing is available only on an object-by-object basis. This makes debug of an application employing multiple components extremely difficult to utilize. Furthermore, typical run-time tracing facility need to be specifically developed for each component to be traced.
The present invention overcomes the disadvantages of the prior art by providing a method of and apparatus for debug of multiple component applications for access of a legacy data base management system via Internet terminal. In order to permit any such access, the present invention must first provide an interface herein referred to generically as a gateway, which translates transaction data transferred from the user over the internet in HTML format into a format from which data base management system commands and inputs may be generated. The gateway must also convert the data base management system responses and outputs for usage on the user""s internet terminal. Thus, as a minimum, the gateway must make these format and protocol conversions. In the preferred embodiment, a number of gateways reside in the web server coupled to the user via the world wide web and coupled to proprietary data base management system.
To make access to a proprietary data base by internet users practical, a sophisticated security system is required to prevent intentional or inadvertent unauthorized access to the sensitive data of an organization. As discussed above, such a security system should provide multiple levels of access to accommodate a variety of authorized user categories. In the preferred embodiment of the present invention, rather than defining several levels of data classification, the different classes of users are managed by identifying a security profile as a portion of those service requests requiring access to secure data. Thus, the security profile accompanies the data/service to be accessed. User information is correlated to the access permitted. This permits certain levels of data to be accessed by one or more of the several classes of user.
In the preferred mode of practicing the present invention, a given user is correlated with a security profile. Upon preparation of the service request which provides internet access to a given portion of the data base, the service request developer specifies which security profiles are permitted access to the data or a portion thereof. The service request developer can subsequently modify the accessibility of any security profile. The utility of the system is greatly enhanced by permitting the service request developer to provide access to predefined portions of the data, rather than being limited to permit or deny access to all of the data involved.
The present invention also permits the system to modify and redefine the security profiles during operation. In accordance with the preferred technique, the system administrator can access an individual user and directly modify the security profile just for that user. This is accomplished by calling up an HTML page for the selected user showing the security profile of record. The system administrator makes changes as appropriate. The Data Wizard Security Service generates script associated with the security profile change which provides the selected user with the new set of access privileges.
Whereas the gateway and the security system are the minimum necessary to permit the most rudimentary form of communication between the internet terminal of the user and the proprietary data base management system, as explained above, the internet is a xe2x80x9cstatelessxe2x80x9d communication system; the addition of the gateway and the security system do not change this statelessness. To unleash the real power of the data base management system, the communication protocol between the data base and the user requires functional interaction between the various data transfers.
The present invention adds security management and state management to this environment. Instead of considering each transfer from the internet user coupled with the corresponding server response as an isolated transaction event as defined by the world wide web, one or more related service requests may be functionally associated in a service request sequence as defined by the data base management system into a dialog.
A repository is established to store the state of the service request sequence. As such, the repository can store intermediate requests and responses, as well as other data associated with the service request sequence. Thus, the repository buffers commands, data, and intermediate products utilized in formatting subsequent data base management service requests and in formatting subsequent data to be available to the user""s browser.
The transaction data in HTML format received by the server from the user, along with the state information stored in the repository, are processed by a service handler into a sequence of service requests in the command language of the data base management system.
Through the use of the repository to store the state of the service request sequence, the service handler to execute data base management commands, the world wide web user is capable of performing each and every data base management function available to any user, including a user from a proprietary terminal having a dedicated communication link which is co-located with the proprietary data base management system hardware and software. In addition, the data base management system user at the world wide web terminal is able to accomplish this, without extensive training concerning the command language of the data base management system.
In accordance with the preferred mode of the present invention, the Cool ICE Data Wizard Join Service provides a web based interface that allows a developer to create a web based service that joins tables from MAPPER Reports, MAPPER runs, databases that are ODBC compliant, and many RDMS, and MAPPER. This service renders the resulting table to the web. This result can be rendered to the web either by a Cool ICE Script or by an Active Server Page.
To assist the developer of such applications, the system of the preferred mode of the present invention employs a tracing facility called xe2x80x9cUTracexe2x80x9d, which allows components from one or more applications to write trace information to a common trace file. Utrace is implemented using both a COM out-of-process executable (Utrace.exe), and a DLL (Utracer.DLL). The Utrace.exe provides the implementation of a COM component that performs the actual file writes to the trace file on behalf of the application. The Utrace component implements a new COM interface called IUTrace that provides the interface to the tracing services. While the IUTrace interface is directly callable from any COM client, a helper class (CUTracer) to this interface is used to provide additional services for an application. The Utracer.DLL provides the CUTracer tracing helper class that offers services for application trace configuration and data formatting.
The present invention separates the tracing process into two processes. The trace formatting provides a standardized facility for generically formatting all trace attributes in a common manner. Generic formatting information consists of such items as PID, Thread ID, and time stamp which are useful to the application developer during debug. This common formatting prepares all attributes for storage and access.
The second process is called trace policy. This identifies the actual trace operations to be performed. The trace policy provides a mechanism for an application to categorize application specific information to be traced. It is the application developer""s responsibility to define the tracing policy for the particular application using the generic trace policy feature provided by this invention. This trace policy is specific in a common header file that is included by components that participate in tracing.